In the paid search advertising industry, content and context are the primary criteria utilized to measure similarity between keywords. As such, these two measures are commonly used in keyword suggestion tools, that is, tools that suggest to an entity (e.g., an advertiser) upon receipt of a first keyword, one or more additional keywords upon which it may want to consider placing a bid as well. For example, if an advertiser places a bid on the keyword “vehicle”, a keyword suggestion tool may also suggest words having similar meaning, e.g., “automobile”, “motorcycle”, “bus”, and the like.
While additional keyword suggestion is beneficial to advertisers seeking to place keywords, content and/or context similarity keyword suggestions provide an advertiser with fairly limited information from which to evaluate their keyword bidding strategies. Additionally, referring back to the above examples the suggested keywords are often words or terms that the advertiser likely could have formulated on their own, simply by being intimately involved in their specific industry.